Methods and compositions for administration of iron

ABSTRACT

The present invention generally relates to treatment of iron-related conditions with iron carbohydrate complexes. One aspect of the invention is a method of treatment of iron-related conditions with a single unit dosage of at least about 0.6 grams of elemental iron via an iron carbohydrate complex. The method generally employs iron carbohydrate complexes with nearly neutral pH, physiological osmolarity, and stable and non-immunogenic carbohydrate components so as to rapidly administer high single unit doses of iron intravenously to patients in need thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application that claims priority toU.S. Non-Provisional application Ser. No. 11/620,986, filed on Jan. 8,2007, which in turn claims priority from U.S. Provisional ApplicationSer. No. 60/757,119, filed on Jan. 6, 2006, each of which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention generally relates to treatment of iron-relatedconditions with iron carbohydrate complexes.

BACKGROUND

Parenteral iron therapy is known to be effective in a variety ofdiseases and conditions including, but not limited to, severe irondeficiency, iron deficiency anemia, problems of intestinal ironabsorption, intestinal iron intolerance, cases where regular intake ofan oral iron preparation is not guaranteed, iron deficiency where thereis no response to oral therapy (e.g., dialysis patients), and situationswhere iron stores are scarcely or not at all formed but would beimportant for further therapy (e.g., in combination witherythropoietin). Geisser et al., Arzneimittelforschung (1992) 42(12),1439-1452. There exist various commercially available parenteral ironformulations. But many currently available parenteral iron drugs, whilepurportedly effective at repleting iron stores, have health risks anddosage limitations associated with their use.

Currently available parenteral iron formulations approved for use in theU.S. include iron dextran (e.g., InFed, Dexferrum), sodium ferricgluconate complex in sucrose (Ferrlecit), and iron sucrose (Venofer).Although serious and life-threatening reactions occur most frequentlywith iron dextran, they are also known to occur with other parenteraliron products. In addition, non-life threatening reactions such asarthralgia, back pain, hypotension, fever, myalgia, pruritus, vertigo,and vomiting also occur. These reactions, while not life-threatening,often preclude further dosing and therefore iron repletion.

Iron dextran, the first parenteral iron product available in the UnitedStates (US), has been associated with an incidence of anaphylactoid-typereactions (i.e., dyspnea, wheezing, chest pain, hypotension, urticaria,angioedema). See generally Fishbane, Am J Kidney Dis (2003) 41(5Suppl),18-26; Landry et al. (2005) Am J Nephrol 25, 400-410, 407. This highincidence of anaphylactoid reactions is believed to be caused by theformation of antibodies to the dextran moiety. Other parenteral ironproducts (e.g., iron sucrose and iron gluconate) do not contain thedextran moiety, and the incidence of anaphylaxis with these products ismarkedly lower. Fishbane, Am J Kidney Dis (2003) 41(5Suppl), 18-26;Geisser et al., Arzneimittelforschung (1992) 42(12), 1439-52. However,the physical characteristics of, for example, iron gluconate and ironsucrose lead to dosage and administration rate limitations. Negativecharacteristics include high pH, high osmolarity, low dosage limits(e.g., maximum 500 mg iron once per week, not exceeding 7 mg iron/kgbody weight), and the long duration of administration (e.g., 100 mg ironover at least 5 minutes as an injection; 500 mg iron over at least 3.5hours as a drip infusion). Furthermore, injectable high molecular masssubstances produce more allergic reactions than the corresponding lowmolecular mass substances. Geisser et al. (1992) Arzneimittelforschung42: 1439-1452.

Ferumoxytol is a newer parenteral iron formulation but limitedinformation is available as to its efficacy and administration. Seee.g., Landry et al. (2005) Am J Nephrol 25, 400-410, 408; and Spinowitzet al. (2005) Kidney Intl 68, 1801-1807; U.S. Pat. No. 6,599,498.

Various pharmacokinetic studies suggest that doses of iron complexeshigher than 200 mg of iron are generally unsuitable and that theconventional therapy model prescribes repeated applications of lowerdoses over several days. See Geisser et al., (1992)Arzneimittelforschung 42: 1439-1452. For example, to achieve ironrepletion under current therapy models, a total dose of 1 g typicallyrequires 5 to 10 sessions over an extended period of time. Thesedelivery modes incur significant expense for supplies such as tubing andinfusate, costly nursing time, multiple administrations, and patientinconvenience.

SUMMARY OF THE INVENTION

Among the various aspects of the present invention is the provision of amethod of treatment of iron-associated diseases, disorders, orconditions with iron formulations. Briefly, therefore, the presentinvention is directed to use of iron carbohydrate complexes that can beadministered parenterally at relatively high single unit dosages,thereby providing a safe and efficient means for delivery of a totaldose of iron in fewer sessions over the course of therapeutic treatment.

The present teachings include methods of treating a disease, disorder,or condition characterized by iron deficiency or dysfunctional ironmetabolism through the administration of at least 0.6 grams of elementaliron via a single unit dosage of an iron carbohydrate complex to asubject that is in need of such therapy.

In various embodiments, the method treats anemia. In some embodiments,the anemia is an iron deficiency anemia, such as that associated withchronic blood loss; acute blood loss; pregnancy; childbirth; childhooddevelopment; psychomotor and cognitive development in children; breathholding spells; heavy uterine bleeding; menstruation; chronic recurrenthemoptysis; idiopathic pulmonary siderosis; chronic internal bleeding;gastrointestinal bleeding; parasitic infections; chronic kidney disease;dialysis; surgery or acute trauma; and chronic ingestion of alcohol,chronic ingestion of salicylates, chronic ingestion of steroids; chronicingestion of non-steroidial anti-inflammatory agents, or chronicingestion of erythropoiesis stimulating agents. In some aspects, theanemia is anemia of chronic disease, such as rheumatoid arthritis;cancer; Hodgkins leukemia; non-Hodgkins leukemia; cancer chemotherapy;inflammatory bowel disease; ulcerative colitis thyroiditis; hepatitis;systemic lupus erythematosus; polymyalgia rheumatica; scleroderma; mixedconnective tissue disease; Sojgren's syndrome; congestive heartfailure/cardiomyopathy; or idiopathic geriatric anemia. In someembodiments, the anemia is due to impaired iron absorption or poornutrition, such as anemia associated with Crohn's Disease; gastricsurgery; ingestion of drug products that inhibit iron absorption; andchronic use of calcium. In various embodiments, the method treatsrestless leg syndrome; blood donation; Parkinson's disease; hair loss;or attention deficit disorder.

In various embodiments, the single dosage unit of elemental iron isbetween at least about 0.6 grams and 2.5 grams. In some embodiments, thesingle dosage unit of elemental iron is at least about 0.7 grams; atleast about 0.8 grams; at least about 0.9 grams; at least about 1.0grams; at least about 1.1 grams; at least about 1.2 grams; at leastabout 1.3 grams; at least about 1.4 grams; at least about 1.5 grams; atleast about 1.6 grams; at least about 1.7 grams; at least about 1.8grams; at least about 1.9 grams; at least about 2.0 grams; at leastabout 2.1 grams; at least about 2.2 grams; at least about 2.3 grams; atleast about 2.4 grams; or at least about 2.5 grams.

In various embodiments, the single dosage unit of elemental iron isadministered in about 15 minutes or less. In some embodiments, thesingle dosage unit of elemental iron is administered in about 10 minutesor less, about 5 minutes or less, or about 2 minutes or less.

In various embodiments, the subject does not experience a significantadverse reaction to the single dosage unit administration.

In various embodiments, the iron carbohydrate complex has a pH betweenabout 5.0 to about 7.0; physiological osmolarity; an iron core size nogreater than about 9 nm; a mean diameter particle size no greater thanabout 35 nm; a blood half-life of between about 10 hours to about 20hours; a substantially non-immunogenic carbohydrate component; andsubstantially no cross reactivity with anti-dextran antibodies.

In various embodiments, the iron carbohydrate complex contains about 24%to about 32% elemental iron; contains about 25% to about 50%carbohydrate; has a molecular weight of about 90,000 daltons to about800,000 daltons, or some combination thereof.

In various embodiments, the iron carbohydrate complex is an ironmonosaccharide complex, an iron disaccharide complex, or an ironpolysaccharide complex. In some embodiments, the iron carbohydratecomplex is iron carboxymaltose complex, iron mannitol complex, ironpolyisomaltose complex, iron polymaltose complex, iron gluconatecomplex, iron sorbitol complex, or an iron hydrogenated dextran complex.In some embodiments, the iron carbohydrate complex is an ironpolyglucose sorbitol carboxymethyl ether complex. In some preferredembodiments, the iron carboxymaltose complex contains about 24% to about32% elemental iron, about 25% to about 50% carbohydrate, and is about100,000 daltons to about 350,000 daltons. In some preferred embodiments,the iron carboxymaltose complex is obtained from an aqueous solution ofiron (III) salt and an aqueous solution of the oxidation product of oneor more maltodextrins using an aqueous hypochlorite solution at a pHvalue within the alkaline range, wherein, when one maltodextrin isapplied, its dextrose equivalent lies between 5 and 20, and when amixture of several maltodextrins is applied, the dextrose equivalentlies between 5 and 20 and the dextrose equivalent of each individualmaltodextrin contained in the mixture lies between 2 and 20. In somepreferred embodiments, the iron carboxymaltose complex has a chemicalformula of [FeO_(x) (OH)_(y) (H₂O)_(z)]_(n) [{(C₆H₁₀O₅)_(m)(C₆H₁₂O₇)}_(l)]_(k), where n is about 103, m is about 8, l is about 11,and k is about 4; contains about 28% elemental iron; and has a molecularweight of about 150,000 Da. In some preferred embodiments, the ironcarboxymaltose complex is polynuclear iron (III)-hydroxide4(R)-(poly-(1→4)-O-α-glucopyranosyl)-oxy-2(R),3(S),5(R),6-tetrahydroxy-hexanoate.

In various embodiments, the iron carbohydrate complex comprises an ironcore with a mean iron core size of no greater than about 9 nm. In someembodiments, the mean iron core size is at least about 1 nm but nogreater than about 9 nm; at least about 3 nm but no greater than about 7nm; or at least about 4 nm but not greater than about 5 nm.

In various embodiments, the mean size of a particle of the ironcarbohydrate complex is no greater than about 35 nm. In someembodiments, the particle mean size is no greater than about 30 nm. Insome embodiments, the particle mean size is no greater than about 25 nm.In some embodiments, the particle mean size is no greater than about 20nm; no greater than about 15 nm; no greater than about 10 nm; or atleast about 6 nm but no greater than about 7 nm.

In various embodiments, the iron carbohydrate complex is administeredparenterally, for example intravenously or intramuscularly. In someembodiments, the iron carbohydrate complex is intravenously infused. Incertain embodiments, the single unit dose of iron carbohydrate complexis intravenously infused at a concentration of about 1000 mg elementaliron in about 200 ml to about 300 ml of diluent, for example, about 250ml of diluent or about 215 ml of diluent. In some embodiments, the ironcarbohydrate complex is intravenously injected as a bolus. In certainembodiments, the iron carbohydrate complex is intravenously injected asa bolus at a concentration of about 1000 mg elemental iron in about 200ml to about 300 ml of diluent, for example, about 250 ml of diluent orabout 215 ml of diluent. In some embodiments, the iron carbohydratecomplex is intramuscularly infused at a concentration of about 1000 mgelemental iron in about 200 ml to about 300 ml of diluent, for example,about 250 ml of diluent or about 215 ml of diluent. In some embodiments,the iron carbohydrate complex is intramuscularly infused at aconcentration of about 500 mg elemental iron in less than about 10 mldiluent.

In various embodiments, the method also includes a second administrationof the iron carbohydrate complex upon recurrence of at least one symptomof the treated disease, disorder, or condition.

In various embodiments, the method also includes a second administrationof the iron carbohydrate complex after 1 day to 12 months after thefirst administration.

In a preferred embodiment, the method of treating a disease, disorder,or condition characterized by iron deficiency or dysfunctional ironmetabolism comprises intravenously administering to a subject in needthereof an iron carboxymaltose complex in a single dosage unit of atleast about 1000 mg of elemental iron in about 200 ml to about 300 ml ofdiluent in about 5 minutes or less; wherein the iron carboxymaltosecomplex comprises an iron core with a mean iron core size of at leastabout 1 nm but no greater than about 9 nm; mean size of a particle ofthe iron carboxymaltose complex is no greater than about 35 nm; and theiron carboxymaltose complex is administered intravenously infused orintravenously injected at a concentration of about 1000 mg elementaliron in about 200 ml to about 300 ml of diluent. In some theseembodiments, the iron carboxymaltose complex is polynuclear iron(III)-hydroxide4(R)-(poly-(1→4)-O-α-glucopyranosyl)-oxy-2(R),3(S),5(R),6-tetrahydroxy-hexanoate.In some these embodiments, the iron carboxymaltose complex is obtainedfrom an aqueous solution of iron (III) salt and an aqueous solution ofthe oxidation product of one or more maltodextrins using an aqueoushypochlorite solution at a pH value within the alkaline range, wherein,when one maltodextrin is applied, its dextrose equivalent lies betweenabout 5 and about 20, and when a mixture of several maltodextrins isapplied, the dextrose equivalent lies between about 5 and about 20 andthe dextrose equivalent of each individual maltodextrin contained in themixture lies between about 2 and about 20.

Other objects and features will be in part apparent and in part pointedout hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Those of skill in the art will understand that the drawings, describedbelow, are for illustrative purposes only. The drawings are not intendedto limit the scope of the present teachings in any way.

FIG. 1 is a series of electron micrographs that depict the particle sizeof three iron carbohydrate complexes. FIG. 1A is an electron micrographdepicting the particle size of Dexferrum (an iron dextran). FIG. 1B isan electron micrograph depicting the particle size of Venofer (an ironsucrose). FIG. 1C is an electron micrograph depicting the particle sizeof polynuclear iron (III)-hydroxide4(R)-(poly-(1→4)-O-α-glucopyranosyl)-oxy-2(R),3(S),5(R),6-tetrahydroxy-hexanoate(“VIT-45”, an iron carboxymaltose complex).

FIG. 2 is a schematic representation of an exemplary iron carboxymaltosecomplex.

DETAILED DESCRIPTION OF THE INVENTION

The present invention makes use of iron carbohydrate complexes that canbe administered parenterally at relatively high single unit dosages forthe therapeutic treatment of a variety of iron-associated diseases,disorders, or conditions. Generally, states indicative of a need fortherapy with high single unit dosages of iron carbohydrate complexesinclude, but are not limited to iron deficiency anemia, anemia ofchronic disease, and states characterized by dysfunctional ironmetabolism. Efficacious treatment of these, and other, diseases andconditions with parenteral iron formulations (supplied at lower singleunit dosages than those described herein) is generally known in the art.See e.g., Van Wyck et al. (2004) J Am Soc Nephrol 15, S91-S92. Thepresent invention is directed to use of iron carbohydrate complexes thatcan be administered parenterally at relatively high single unit dosages,thereby providing a safe and efficient means for delivery of a totaldose of iron in fewer sessions over the course of therapeutic treatment.

Iron deficiency anemia is associated with, for example, chronic bloodloss; acute blood loss; pregnancy; childbirth; childhood development;psychomotor and cognitive development in children; breath holdingspells; heavy uterine bleeding; menstruation; chronic recurrenthemoptysis; idiopathic pulmonary siderosis; chronic internal bleeding;gastrointestinal bleeding; parasitic infections; chronic kidney disease;dialysis; surgery or acute trauma; and chronic ingestion of alcohol,chronic ingestion of salicylates, chronic ingestion of steroids; chronicingestion of non-steroidial anti-inflammatory agents, or chronicingestion of erythropoiesis stimulating agents.

Anemia of chronic disease is associated with, for example, rheumatoidarthritis; cancer; Hodgkins leukemia; non-Hodgkins leukemia; cancerchemotherapy; inflammatory bowel disease; ulcerative colitisthyroiditis; hepatitis; systemic lupus erythematosus; polymyalgiarheumatica; scleroderma; mixed connective tissue disease; Sojgren'ssyndrome; congestive heart failure/cardiomyopathy; and idiopathicgeriatric anemia.

Anemia is also associated with, for example, Crohn's Disease; gastricsurgery; ingestion of drug products that inhibit iron absorption; andchronic use of calcium.

States characterized by dysfunctional iron metabolism and treatable withthe single unit dosages of iron carbohydrate complexes described hereininclude, but are not limited to, restless leg syndrome; blood donation;Parkinson's disease; hair loss; and attention deficit disorder.

Again, each of the above listed states, diseases, disorders, andconditions, as well as others, can benefit from the treatmentmethodologies described herein. Generally, treating a state, disease,disorder, or condition includes preventing or delaying the appearance ofclinical symptoms in a mammal that may be afflicted with or predisposedto the state, disease, disorder, or condition but does not yetexperience or display clinical or subclinical symptoms thereof. Treatingcan also include inhibiting the state, disease, disorder, or condition,e.g., arresting or reducing the development of the disease or at leastone clinical or subclinical symptom thereof. Furthermore, treating caninclude relieving the disease, e.g., causing regression of the state,disease, disorder, or condition or at least one of its clinical orsubclinical symptoms.

The benefit to a subject to be treated is either statisticallysignificant or at least perceptible to the patient or to the physician.Measures of efficacy of iron replacement therapy are generally based onmeasurement of iron-related parameters in blood. The aim of treatment isusually to return both Hb and iron stores to normal levels. Thus,efficacy of iron replacement therapy can be interpreted in terms of theability to normalise Hb levels and iron stores. The effectiveness oftreatment with one or more single unit doses of iron carbohydratecomplex, as described herein, can be demonstrated, for example, byimprovements in ferritin and transferrin saturation, and in raisinghemoglobin levels in anemic patients. Iron stores can be assessed byinterpreting serum ferritin levels. TfS is frequently used, in addition,to diagnose absolute or functional iron deficiencies. In patients withiron deficiency, serum transferrin is elevated and will decreasefollowing successful iron treatment.

Administration

Methods of treatment of various diseases, disorders, or conditions withiron complex compositions comprise the administration of the complex insingle unit dosages of at least 0.6 grams of elemental iron to about atleast 2.5 grams of elemental iron. Administration of single unit dosagescan be, for example, over pre-determined time intervals or in responseto the appearance and/or reappearance of symptoms. For example, the ironcarbohydrate complex can be re-administered upon recurrence of at leastone symptom of the disease or disorder. As another example, the ironcarbohydrate complex can be re-administered at some time period afterthe initial administration (e.g., after 4 days to 12 months).

Any route of delivery of the single unit dose of iron carbohydratecomplex is acceptable so long as iron from the iron complex is releasedsuch that symptoms are treated. The single unit dose of ironcarbohydrate complex can be administered parenterally, for exampleintravenously or intramuscularly. Intravenous administration can bedelivered as a bolus or preferably as an infusion. For example, thesingle unit dose of iron carbohydrate complex can be intravenouslyinfused at a concentration of about 1000 mg elemental iron in about 200ml to about 300 ml of diluent, preferably about 215 ml of diluent orabout 250 ml of diluent. The iron carbohydrate complex can beintravenously injected as a bolus. For example, the iron carbohydratecomplex can be intravenously injected as a bolus at a concentration ofabout 1000 mg elemental iron in about 200 ml to about 300 ml of diluent,preferably about 215 ml of diluent or about 250 ml of diluent. The ironcarbohydrate complex can be intramuscularly infused at a concentrationof, for example, about 1000 mg elemental iron in about 200 ml to about300 ml of diluent, preferably, about 250 ml of diluent or about 215 mlof diluent. If applied as an infusion, the iron carbohydrate complex canbe diluted with sterile saline (e.g., polynuclear iron (III)-hydroxide4(R)-(poly-(1→4)-O-α-glucopyranosyl)-oxy-2(R),3(S),5(R),6-tetrahydroxy-hexanoate(“VIT-45”) 0.9% m/V NaCl or 500 mg iron in up to 250 mL NaCl). The ironcarbohydrate complex can be intravenously injected as a bolus withoutdilution. As an example, the iron carbohydrate complex can beintramuscularly injected at a concentration of about 500 mg elementaliron in less than about 10 ml diluent, preferably about 5 ml.

Generally, total iron dosage will depend on the iron deficit of thepatient. One skilled in the art can tailor the total iron dose requiredfor a subject while avoiding iron overload, as overdosing with respectto the total required amount of iron has to be avoided, as is the casefor all iron preparations.

The total iron dosage can be delivered as a single unit dosage or aseries of single unit dosages. An appropriate single unit dosage levelwill generally be at least 0.6 grams of elemental iron, particularly atleast 0.7 grams; at least 0.8 grams; at least 0.9 grams; at least 1.0grams; at least 1.1 grams; at least 1.2 grams; at least 1.3 grams; atleast 1.4 grams; at least 1.5 grams; at least 1.6 grams; at least 1.7grams; at least 1.8 grams; at least 1.9 grams; at least 2.0 grams; atleast 2.1 grams; at least 2.2 grams; at least 2.3 grams; at least 2.4grams; or at least 2.5 grams. For example, a single unit dosage is atleast 1.0 grams of elemental iron. As another example, a single unitdosage is at least 1.5 grams of elemental iron. As a further example, asingle unit dosage is at least 2.0 grams of elemental iron. In yetanother example, a single unit dosage is at least 2.5 grams of elementaliron.

An appropriate single unit dosage level can also be determined on thebasis of patient weight. For example, an appropriate single unit dosagelevel will generally be at least 9 mg of elemental iron per kg bodyweight, particularly at least 10.5 mg/kg, at least 12 mg/kg, at least13.5 mg/kg, at least 15 mg/kg, at least 16.5 mg/kg, at least 18 mg/kg,at least 19.5 mg/kg, at least 21 mg/kg, at least 22.5 mg/kg, at least 24mg/kg, at least 25.5 mg/kg, at least 27 mg/kg, at least 28.5 mg/kg, atleast 30 mg/kg, at least 31.5 mg/kg, at least 33 mg/kg, at least 34.5mg/kg, at least 36 mg/kg, or at least 37.5 mg/kg.

Preferably, a single unit dosage can be administered in 15 minutes orless. For example, the single unit dosage can be administered in 14minutes or less, 13 minutes or less, 12 minutes or less, 11 minutes orless, 10 minutes or less, 9 minutes or less, 8 minutes or less, 7minutes or less, 6 minutes or less, 5 minutes or less, 4 minutes orless, 3 minutes or less, or 2 minutes or less.

Administration of iron can occur as a one-time delivery of a single unitdose or over a course of treatment involving delivery of multiple singleunit doses. Multiple single unit doses can be administered, for example,over pre-determined time intervals or in response to the appearance andreappearance of symptoms. The frequency of dosing depends on the diseaseor disorder being treated, the response of each individual patient, andthe administered amount of elemental iron. An appropriate regime ofdosing adequate to allow the body to absorb the iron from thebloodstream can be, for example, a course of therapy once every day toonce every eighteen months.

Such consecutive single unit dosing can be designed to deliver arelatively high total dosage of iron over a relatively low period oftime. For example, a single unit dose (e.g., 1000 mg) can beadministered every 24 hours. As illustration, a total dose of 2000,2500, 3000, 3500, 4000, 4500, or 5000 mg of elemental iron can bedelivered via consecutive daily single unit doses of about 600 mg toabout 1000 mg of elemental iron. Given that a single unit dose of 1000mg can be intravenously introduced into a patient in a concentrated formover, for example, two minutes, such administrative protocol provides apractitioner and patient with an effective, efficient, and safe means todeliver elemental iron.

As another example, a single unit dose can be administered every 3-4days. As a further example, a single unit dose can be administered onceper week. Alternatively, the single unit doses of iron complex may beadministered ad hoc, that is, as symptoms reappear, as long as safetyprecautions are regarded as practiced by medical professionals.

It will be understood, however, that the specific dose and frequency ofadministration for any particular patient may be varied and depends upona variety of factors, including the activity of the employed ironcomplex, the metabolic stability and length of action of that complex,the age, body weight, general health, sex, diet, mode and time ofadministration, rate of excretion, drug combination, the severity andnature of the particular condition, and the host undergoing therapy.

The following provides but a few examples of treatment protocols forvarious diseases or disorders.

Iron carbohydrate complex can be given as a single unit dose for thetreatment of Restless Leg Syndrome. For example, 1000 mg of elementaliron from an iron carboxymaltose (e.g., polynuclear iron (III)-hydroxide4(R)-(poly-(1→4)-O-α-glucopyranosyl)-oxy-2(R),3(S),5(R),6-tetrahydroxy-hexanoate)can be intravenously injected as a single dose (e.g., 1.5-5 mg iron/mlin normal saline) to a subject suffering from Restless Leg Syndrome. Asingle intravenous treatment can provide relief of symptoms for anextended period of time, approximately two to twelve months, althoughrelief may be granted for shorter or longer periods. See U.S. PatentPub. No. 2004/0180849, incorporated herein by reference. If desired,post-infusion changes in central nervous system iron status can bemonitored using measurements of cerebral spinal fluid (CSF) ferritin(and other iron-related proteins) and of brain iron stores using MRI.Post-infusion changes in Restless Leg Syndrome are assessed usingstandard subjective (e.g., patient diary, rating scale) and objective(e.g., P50, SIT, Leg Activity Meters) measures of clinical status. Ifdesired, to better evaluate RLS symptom amelioration, CSF and serum ironvalues, MRI measures of brain iron and full clinical evaluations withsleep and immobilization tests are obtained prior to treatment,approximately two weeks after treatment, and again twelve months lateror when symptoms return. Clinical ratings, Leg Activity Meter recordingsand serum ferritin are obtained monthly after treatment. CSF ferritinchanges can also be used to assess symptom dissipation.

Iron carbohydrate complex can be given as a single unit dose for thetreatment of iron deficiency anemia secondary to heavy uterine bleeding.For example, a single unit dose of 1,000 mg of elemental iron from aniron carboxymaltose in about 250 cc normal saline can be intravenouslyinjected into a subject suffering from iron deficiency anemia secondaryto heavy uterine bleeding over 15 minutes every week until a calculatediron deficit dose has been administered. The iron deficit dose can becalculated as follows:If baseline TSAT<20% or Baseline Ferritin<50 ng/ml: Dose=Baseline weight(kg)×(15-Baseline Hgb [g/dL])×2.4+500 mgORIf baseline TSAT>20% and Baseline Ferritin>50 ng/mL: Dose=Baselineweight (kg)×(15-Baseline Hgb [g/dL])×2.4

-   -   (NOTE: Baseline Hgb equals the average of the last two central        lab Hgb's)

Iron carbohydrate complex can be given as a single unit dose for thetreatment of iron deficiency anemia. A subject diagnosed as sufferingfrom iron deficiency anemia can be, for example, intravenously injectedwith a dose of 1,000 mg of iron as VIT-45 (or 15 mg/kg for weight<66 kg)in 250 cc of normal saline over 15 minutes. Subjects with irondeficiency anemia secondary to dialysis or non-dialysisdependent-Chronic Kidney Disease (CKD) as per K/DOQI guidelines willgenerally have Hgb<12 g/dL; TSAT<25%; and Ferritin<300 ng/mL. Subjectswith iron deficiency anemia secondary to Inflammatory Bowel Disease willgenerally have Hgb<12 g/dL; TSAT<25%; and Ferritin<300 ng/mL. Subjectswith iron deficiency anemia secondary to other conditions will generallyhave Hgb<12 g/dL; TSAT<25%; and Ferritin<100 ng/mL.

Subject in Need Thereof

Single unit dosages of intravenous iron described herein can beadministered to a subject where there is a clinical need to deliver ironrapidly or in higher doses and/or in subjects with functional irondeficiency such as those on erythropoietin therapy. A determination ofthe need for treatment with parenteral iron is within the abilities ofone skilled in the art. For example, need can be assessed by monitoringa patient's iron status. The diagnosis of iron deficiency can be basedon appropriate laboratory tests, for example, haemoglobin (Hb), serumferritin, serum iron, transferrin saturation (TfS), and hypochromic redcells.

A determination of the need for treatment with high dosages ofparenteral iron can be also be determined through diagnosis of a patientas suffering from a disease, disorder, or condition that is associatedwith iron deficiency or dysfunctional iron metabolism. For example, manychronic renal failure patients receiving erythropoietin will requireintravenous iron to maintain target iron levels. As another example,most hemodialysis patients will require repeated intravenous ironadministration, due to dialysis-associated blood loss and resultingnegative iron balance.

Monitoring frequency can depend upon the disease, disorder, or conditionthe patient is afflicted with or at risk for. For example, in a patientinitiating erythropoietin therapy, iron indices are monitored monthly.As another example, in patients who have achieved target range Hb or arereceiving intravenous iron therapy, TSAT and ferritin levels can bemonitored every 3 months.

A patient's iron status can be indicative of an absolute or a functionaliron deficiency, both of which can be treated with the compositions andmethods described herein. An absolute iron deficiency occurs when aninsufficient amount of iron is available to meet the body'srequirements. The insufficiency may be due to inadequate iron intake,reduced bioavailability of dietary iron, increased utilization of iron,or chronic blood loss. Prolonged iron deficiency can lead to irondeficiency anemia—a microcytic, hypochromic anemia in which there areinadequate iron stores. Absolute iron deficiency is generally indicatedwhere TSAT<20% and Ferritin<100 ng/mL.

Functional iron deficiency can occur where there is a failure to releaseiron rapidly enough to keep pace with the demands of the bone marrow forerythropoiesis, despite adequate total body iron stores. In these cases,ferritin levels may be normal or high, but the supply of iron to theerythron is limited, as shown by a low transferrin saturation and anincreased number of microcytic, hypochromic erythrocytes. Functionaliron deficiency can be characterized by the following characteristics:Inadequate hemoglobin response to erythropoietin; Serum ferritin may benormal or high; Transferrin saturation (TSAT) usually <20%; and/orreduced mean corpuscular volume (MCV) or mean corpuscular hemoglobinconcentration (MCHC) in severe cases. Functional iron deficiency (i.e.,iron stores are thought to be adequate but unavailable for irondelivery) is generally indicated where TSAT<20% and Ferritin>100 ng/mL.

Assessing the need for intravenous iron therapy as described herein canbe according to the National Kidney Foundation's Kidney Disease OutcomesQuality Initiative. See NKF-K/DOQI, Clinical Practice Guidelines forAnemia of Chronic Kidney Disease (2000); Am J Kidney Dis (2001) 37(supp1), S182-S238. The DOQI provides optimal clinical practices for thetreatment of anemia in chronic renal failure. The DOQI guidelinesspecify intravenous iron treatment of kidney disease based onhemoglobin, transferrin saturation (TSAT), and ferritin levels.

Assessment of need for intravenous iron therapy can also be according toa patient's target iron level. For example, the target hemoglobin levelof a patient can be selected as 11.0 g/dL to 12.0 g/dL (hematocritapproximately 33% to 36%). To achieve target hemoglobin with optimumerythropoietin doses, sufficient iron, supplied via an iron carbohydratecomplex, is provided to maintain TSAT≧20% and ferritin≧100 ng/mL. Inerythropoietin-treated patients, if TSAT levels are below 20%, thelikelihood that hemoglobin will rise or erythropoietin doses fall afteriron administration is high. Achievement of target hemoglobin levelswith optimum erythropoietin doses is associated with providingsufficient iron to maintain TSAT above 20%.

Iron therapy can be given to maintain target hemoglobin while preventingiron deficiency and also preventing iron overload. Adjusting dosage ofiron to maintain target levels of hemoglobin, hematocrit, and laboratoryparameters of iron storage is within the normal skill in the art. Forexample, where a patient is anemic or iron deficient, intravenous ironcan be administered when a patient has a ferritin<800, a TSAT<50, and/ora Hemoglobin<12. Iron overload can be avoided by withholding iron forTSAT>50% and/or ferritin>800 ng/mL.

Where a patient is not anemic or iron deficient but is in need of ironadministration, for example a patient suffering from Restless LegSyndrome, hemoglobin and TSAT levels are not necessarily relevant, whileferritin>800 can still provides a general cut off point foradministration.

Iron Carbohydrate Complex

Iron carbohydrate complexes are commercially available, or have wellknown syntheses. Examples of iron carbohydrate complexes include ironmonosaccharide complexes, iron disaccharide complexes, ironoligosaccharide complexes, and iron polysaccharide complexes, such as:iron carboxymaltose, iron sucrose, iron polyisomaltose (iron dextran),iron polymaltose (iron dextrin), iron gluconate, iron sorbitol, ironhydrogenated dextran, which may be further complexed with othercompounds, such as sorbitol, citric acid and gluconic acid (for exampleiron dextrin-sorbitol-citric acid complex and iron sucrose-gluconic acidcomplex), and mixtures thereof.

Applicants have discovered that certain characteristics of ironcarbohydrate complexes make them amenable to administration at dosagesfar higher than contemplated by current administration protocols.Preferably, iron carbohydrate complexes for use in the methods describedherein are those which have one or more of the followingcharacteristics: a nearly neutral pH (e.g., about 5 to about 7);physiological osmolarity; stable carbohydrate component; an iron coresize no greater than about 9 nm; mean diameter particle size no greaterthan about 35 nm, preferably about 25 nm to about 30 nm; slow andcompetitive delivery of the complexed iron to endogenous iron bindingsites; serum half-life of over about 7 hours; low toxicity;non-immunogenic carbohydrate component; no cross reactivity withanti-dextran antibodies; and/or low risk ofanaphylactoid/hypersensitivity reactions.

It is within the skill of the art to test various characteristics ofiron carbohydrate complexes as so determine amenability to use in themethods described herein. For example, pH and osmolarity arestraightforward determinations performed on a sample formulation.Likewise, techniques such as electron micrograph imaging, transmissionelectron microscopy, and atomic force microscopy provide direct methodsto analyze both iron core and particle size. See e.g., FIG. 1; Table 1.The stability of the carbohydrate complex can be assessed throughphysicochemical properties such as kinetic characteristics,thermodynamic characteristics, and degradation kinetics. See Geisser etal., Arzneimittelforschung (1992) 42(12), 1439-1452. Useful techniquesto assess physical and electronic properties include absorptionspectroscopy, X-ray diffraction analysis, transmission electronmicroscopy, atomic force microscopy, and elemental analysis. SeeKudasheva et al. (2004) J Inorg Biochem 98, 1757-1769. Pharmacokineticscan be assessed, for example, by iron tracer experiments.Hypersensitivity reactions can be monitored and assessed as describedin, for example, Bailie et al. (2005) Nephrol Dial Transplant, 20(7),1443-1449. Safety, efficacy, and toxicity in human subjects can beassessed, for example, as described in Spinowitz et al. (2005) KidneyIntl 68, 1801-1807.

A particularly preferred iron carbohydrate complex will have a pHbetween 5.0-7.0; physiological osmolarity; an iron core size no greaterthan 9 nm; mean diameter particle size no greater than 30 nm; serumhalf-life of over 10 hours; a non-immunogenic carbohydrate component;and no cross reactivity with anti-dextran antibodies. One example of apreferred iron carbohydrate complex for use in the methods describedherein is an iron carboxy-maltose complex (e.g., polynuclear iron(III)-hydroxide4(R)-(poly-(1→4)-O-α-glucopyranosyl)-oxy-2(R),3(S),5(R),6-tetrahydroxy-hexanoate,“VIT-45”). Another example of a preferred iron carbohydrate complex foruse in the methods described herein is a carboxyalkylated reducedpolysaccharide iron oxide complex (e.g., ferumoxytol, described in U.S.Pat. No. 6,599,498).

Preferably, an iron carbohydrate complex, for use in methods disclosedherein, contains about 24% to about 32% elemental iron, more preferablyabout 28% elemental iron. Preferably, an iron carbohydrate complex, foruse in methods disclosed herein, contains about 25% to about 50%carbohydrate (e.g., total glucose). Preferably, an iron carbohydratecomplex, for use in methods disclosed herein, is about 90,000 daltons toabout 800,000 daltons, more preferably 100,000 daltons to about 350,000daltons.

Iron Carboxymaltose Complex

One preferred iron carbohydrate complex for use in the methods describedherein is an iron carboxymaltose complex. An example of an ironcarboxymaltose complex is polynuclear iron (III)-hydroxide4(R)-(poly-(1→4)-O-α-glucopyranosyl)-oxy-2(R),3(S),5(R),6-tetrahydroxy-hexanoate(“VIT-45”). VIT-45 is a Type I polynuclear iron (III) hydroxidecarbohydrate complex that can be administered as parenteral ironreplacement therapy for the treatment of various anemia-relatedconditions as well as other iron-metabolism related conditions. VIT-45can be represented by the chemical formula: [FeOx(OH)y(H2O)z]n[{(C6H10O5)m (C6H12O7)}l]k, where n is about 103, m is about 8, l isabout 11, and k is about 4). The molecular weight of VIT-45 is about150,000 Da. An exemplary depiction of VIT-45 is provided in FIG. 2.

The degradation rate and physicochemical characteristics of the ironcarbohydrate complex (e.g., VIT-45) make it an efficient means ofparenteral iron delivery to the body stores. It is more efficient andless toxic than the lower molecular weight complexes such as ironsorbitol/citrate complex, and does not have the same limitations of highpH and osmolarity that leads to dosage and administration ratelimitations in the case of, for example, iron sucrose and irongluconate.

The iron carboxymaltose complex (e.g., VIT-45) generally does notcontain dextran and does not react with dextran antibodies; therefore,the risk of anaphylactoid/hypersensitivity reactions is very lowcompared to iron dextran. The iron carboxymaltose complex (e.g., VIT-45)has a nearly neutral pH (5.0 to 7.0) and physiological osmolarity, whichmakes it possible to administer higher single unit doses over shortertime periods than other iron-carbohydrate complexes. The ironcarboxymaltose complex (e.g., VIT-45) can mimic physiologicallyoccurring ferritin. The carbohydrate moiety of iron carboxymaltosecomplex (e.g., VIT-45) is metabolized by the glycolytic pathway. Likeiron dextran, the iron carboxymaltose complex (e.g., VIT-45) is morestable than iron gluconate and sucrose. The iron carboxymaltose complex(e.g., VIT-45) produces a slow and competitive delivery of the complexediron to endogenous iron binding sites resulting in an acute toxicityone-fifth that of iron sucrose. These characteristics of the ironcarboxymaltose complex (e.g., VIT-45) allow administration of highersingle unit doses over shorter periods of time than, for example, irongluconate or iron sucrose. Higher single unit doses can result in theneed for fewer injections to replete iron stores, and consequently isoften better suited for outpatient use.

After intravenous administration, the iron carboxymaltose complex (e.g.,VIT-45) is mainly found in the liver, spleen, and bone marrow.Pharmacokinetic studies using positron emission tomography havedemonstrated a fast initial elimination of radioactively labeled iron(Fe) ⁵²Fe/⁵⁹Fe VIT-45 from the blood, with rapid transfer to the bonemarrow and rapid deposition in the liver and spleen. See e.g., Besharaet al. (2003) Br J Haematol 2003; 120(5): 853-859. Eight hours afteradministration, 5 to 20% of the injected amount was observed to be stillin the blood, compared with 2 to 13% for iron sucrose. The projectedcalculated terminal half-life (t_(1/2)) was approximately 16 hours,compared to 3 to 4 days for iron dextran and 6 hours for iron sucrose.

The iron in the iron carboxymaltose complex (e.g., VIT-45) slowlydissociates from the complex and can be efficiently used in the bonemarrow for Hgb synthesis. Under VIT-45 administration, red cellutilization, followed for 4 weeks, ranged from 61% to 99%. Despite therelatively higher uptake by the bone marrow, there was no saturation ofmarrow transport systems. Thus, high red cell utilization of ironcarboxymaltose complex occurs in anemic patients. In addition, thereticuloendothelial uptake of this complex reflects the safety ofpolysaccharide complexes. Non-saturation of transport systems to thebone marrow indicated the presence of a large interstitial transportpool (e.g., transferrin).

Other studies in patients with iron deficiency anemia revealed increasesin exposure roughly proportional with VIT-45 dose (maximal total serumiron concentration was approximately 150 μg/mL and 320 μg/mL following500 mg and 1000 mg doses, respectively). In these studies, VIT-45demonstrated a monoexponential elimination pattern with a t_(1/2) in therange 7 to 18 hours, with negligible renal elimination.

Single-dose toxicity studies have demonstrated safety and tolerance inrodents and dogs of intravenous doses of an iron carboxymaltose complex(VIT-45) up to 60 times more than the equivalent of an intravenousinfusion of 1,000 mg iron once weekly in humans. Pre-clinical studies indogs and rats administered VIT-45 in cumulative doses up to 117 mgiron/kg body weight over 13 weeks showed no observed adverse effectlevel in dose-related clinical signs of iron accumulation in the liver,spleen, and kidneys. No treatment-related local tissue irritation wasobserved in intra-arterial, perivenous, or intravenous tolerance studiesin the rabbit. In vitro and in vivo mutagenicity tests provided noevidence that VIT-45 is clastogenic, mutagenic, or causes chromosomaldamage or bone marrow cell toxicity. There were no specific responses toVIT-45 in a dextran antigenicity test.

Approximately 1700 subjects have been treated with an ironcarboxymaltose complex (VIT-45) in open label clinical trials (see e.g.,Example 5). Many of these subjects have received at least one dose of 15mg/kg (up to a maximum dose of 1,000 mg) of VIT-45 over 15 minutesintravenously. Few adverse events and no serious adverse events orwithdrawals due to adverse events related to VIT-45 administration havebeen reported. No clinically relevant adverse changes in safetylaboratories have been seen.

The physicochemical characteristics of the iron carboxymaltose complex(e.g., VIT-45), the pattern of iron deposition, and the results of theabove described studies demonstrate that iron carboxymaltose complex canbe safely administered at high single unit therapeutic doses asdescribed herein.

Polyglucose Sorbitol Carboxymethyl Ether-Coated Non-StoichiometricMagnetite

Another preferred iron carbohydrate complex for use in the methodsdescribed herein is a polyglucose sorbitol carboxymethyl ether-coatednon-stoichiometric magnetite (e.g., “ferumoxytol”). Ferumoxytol is knownin the art to be effective for treating anemia (at single unit doseslower than described herein). See e.g., Spinowitz et al. (2005) KidneyIntl 68, 1801-1807. Ferumoxytol is a superparamagnetic iron oxide thatis coated with a low molecular weight semi-synthetic carbohydrate,polyglucose sorbitol carboxymethyl ether. Ferumoxytol and its synthesisare described in U.S. Pat. No. 6,599,498, incorporated herein byreference. Safety, efficacy, and pharmacokinetics of ferumoxytol are asdescribed, for example, in Landry et al. (2005) Am J Nephrol 25,400-410, 408; and Spinowitz et al. (2005) Kidney Intl 68, 1801-1807.

The iron oxide of ferumoxytol is a superparamagnetic form ofnon-stoichiometric magnetite with a crystal size of 6.2 to 7.3 nm.Average colloidal particle size can be about 30 nm, as determined bylight scattering. Molecular weight is approximately 750 kD. Theosmolarity of ferumoxytol is isotonic at 297 mOsm/kg and the pH isneutral. The blood half-life of ferumoxytol is approximately 10-14hours. It has been previously reported that ferumoxytol can be given bydirect intravenous push over 1-5 minutes in doses up to 1,800 mgelemental iron per minute, with maximal total dose up to 420 mg perinjection. Landry et al. (2005) Am J Nephrol 25, 400-410, 408.

Core and Particle Size

Intravenous iron agents are generally spheroidal iron-carbohydratenanoparticles. At the core of each particle is an iron-oxyhydroxide gel.The core is surrounded by a shell of carbohydrate that stabilizes theiron-oxyhydroxide, slows the release of bioactive iron, and maintainsthe resulting particles in colloidal suspension. Iron agents generallyshare the same core chemistry but differ from each other by the size ofthe core and the identity and the density of the surroundingcarbohydrate. See Table 1; FIG. 1.

TABLE 1 Core and Particle Size of Iron Carbohydrate Complexes Iron (III)Control Release Test Size of the Particle (nm) +/− SEM T₇₅ (min) Ironcore Total Particle Dexferrum 122.5 11.8 ± 4   27 ± 6  (an iron dextran)VIT -45 (an iron 117.8 4.4 ± 1.4 6.7 ± 2.5 carboxymaltose) Venofer 10.22.8 ± 1   6.5 ± 4   (an iron sucrose)

Differences in core size and carbohydrate chemistry can determinepharmacological and biological differences, including clearance rateafter injection, iron release rate in vitro, early evidence of ironbioactivity in vivo, and maximum tolerated dose and rate of infusion.

One of the primary determinants of iron bioactivity is the size of thecore and the surface area to volume ratio. Generally, the rate of labileiron release in each agent is inversely related to the size of its ironcore. Van Wyck (2004) J. Am. Soc. Nephrology 15, S107-S111, S109.Furthermore, in vitro iron donation to transferrin is inversely relatedto core size. Core size can depend upon the number of iron atomscontained within. For example, the number of iron atoms contained withina 1 nm core is calculated to be 13, while a 10 nm core is calculated tocontain 12770 iron atoms. Where agents share the same core chemistry,the rate of iron release per unit surface area is likely similar,differing perhaps by the strength of the carbohydrate ligand-core ironbound. But for the same total amount of core iron, surface areaavailable for iron release increases dramatically as core radiusdecreases. That is to say, for equal amounts of iron, the smaller thecore, the greater the surface area available for iron release. Ofcourse, the explanation for this non-linear trend is the fact thatvolume is radius cubed. In short, a collection of many small spheresexposes a greater total surface area than does a collection of an equalmass of fewer, larger spheres.

A smaller iron core size of an iron complex administered for thetreatment of various diseases, disorders, or conditions allows widerdistribution through tissues, a greater rate of labile iron release, andincreased in vitro iron donation to transferrin. Furthermore, the ironcomplex is more evenly distributed and metabolizes faster due to thesmaller core size. But if the core size is too small, the iron complexcan move into cells unable to metabolize iron. In one embodiment, aniron complex with a mean iron core size of no greater than about 9 nm isadministered. In various embodiments, mean iron core size is less thanabout 9 nm but greater than about 1 nm, about 2 nm, about 3 nm, about 4nm, about 5 nm, about 6 nm, about 7 nm, or about 8 nm. Mean iron coresize can be, for example, between about 1 nm and about 9 nm; betweenabout 3 nm and about 7 nm; or between about 4 nm and about 5 nm.

The molecular weight (i.e., the whole molecular weight of the agent) isconsidered a primary determinant in the pharmacokinetics, or in otherwords, how quickly it is cleared from the blood stream. The amount oflabile (i.e., biologicaly available) iron is inversely correlated withthe molecular weight of the iron-carbohydrate complex. Van Wyck (2004)J. Am. Soc. Nephrology 15, S107-S111, S109. That is to say, themagnitude of labile iron effect is greatest in iron-carbohydratecompounds of lowest molecular weight and least in those of the highestmolecular weight. Generally, there is a direct relationship between themolecular weight of the agent and the mean diameter of the entireparticle (i.e., the iron core along with the carbohydrate shell). Invarious embodiments, the mean diameter size of a particle of the ironcarbohydrate complex is no greater than about 35 nm. For example, theparticle mean size can be no greater than about 30 nm. As anotherexample, the particle mean size can be no greater than about 25 nm. Asanother example, the particle mean size can be no greater than about 20nm. As another example, the particle mean size can be no greater thanabout 15 nm. As a further example, the particle mean size can be nogreater than about 10 nm. As another example, the particle mean size canbe no greater than about 7 nm.

Absence of Significant Adverse Reaction to the Single Dosage UnitAdministration

Generally, a safe and effective amount of an iron carbohydrate complexis, for example, that amount that would cause the desired therapeuticeffect in a patient while minimizing undesired side effects. The dosageregimen will be determined by skilled clinicians, based on factors suchas the exact nature of the condition being treated, the severity of thecondition, the age and general physical condition of the patient, and soon. Generally, treatment-emergent adverse events will occur in less thanabout 5% of treated patients. For example, treatment-emergent adverseevents will occur in less than 4% or 3% of treated patients. Preferably,treatment-emergent adverse events will occur in less than about 2% oftreated patients.

For example, minimized undesirable side effects can include thoserelated to hypersensitivity reactions, sometimes classified as suddenonset closely related to the time of dosing, including hypotension,bronchospasm, layngospasm, angioedema or uticaria or several of thesetogether. Hypersensitivity reactions are reported with all currentintravenous iron products independent of dose. See generally Bailie etal. (2005) Nephrol Dial Transplant, 20(7), 1443-1449. As anotherexample, minimized undesirable side effects can include those related tolabile iron reactions, sometimes classified as nausea, vomiting, cramps,back pain, chest pain, and/or hypotension. Labile iron reactions aremore common with iron sucrose, iron gluconate, and iron dextran whendoses are large and given fast.

Pharmaceutical Formulations

In many cases, a single unit dose of iron carbohydrate complex may bedelivered as a simple composition comprising the iron complex and thebuffer in which it is dissolved. However, other products may be added,if desired, for example, to maximize iron delivery, preservation, or tooptimize a particular method of delivery.

A “pharmaceutically acceptable carrier” includes any and all solvents,dispersion media, coatings, antibacterial and anti-fungal agents,isotonic and absorption delaying agents, and the like, compatible withpharmaceutical administration (see e.g., Banker, Modern Pharmaceutics,Drugs and the Pharmaceutical Sciences, 4th ed. (2002) ISBN 0824706749;Remington The Science and Practice of Pharmacy, 21st ed. (2005) ISBN0781746736). Preferred examples of such carriers or diluents include,but are not limited to, water, saline, Finger's solutions and dextrosesolution. Supplementary active compounds can also be incorporated intothe compositions. For intravenous administration, the iron carbohydratecomplex is preferably diluted in normal saline to approximately 2-5mg/ml. The volume of the pharmaceutical solution is based on the safevolume for the individual patient, as determined by a medicalprofessional.

An iron complex composition of the invention for administration isformulated to be compatible with the intended route of administration,such as intravenous injection. Solutions and suspensions used forparenteral, intradermal or subcutaneous application can include asterile diluent, such as water for injection, saline solution,polyethylene glycols, glycerine, propylene glycol or other syntheticsolvents; antibacterial agents such as benzyl alcohol or methylparabens; antioxidants such as ascorbic acid or sodium bisulfite;buffers such as acetates, citrates or phosphates, and agents for theadjustment of tonicity such as sodium chloride or dextrose. The pH canbe adjusted with acids or bases, such as hydrochloric acid or sodiumhydroxide. Preparations can be enclosed in ampules, disposable syringesor multiple dose vials made of glass or plastic.

Pharmaceutical compositions suitable for injection include sterileaqueous solutions or dispersions for the extemporaneous preparation ofsterile injectable solutions or dispersion. For intravenousadministration, suitable carriers include physiological saline,bacteriostatic water, Cremophor EL™ (BASF; Parsippany, N.J.) orphosphate buffered saline (PBS). The composition must be sterile andshould be fluid so as to be administered using a syringe. Suchcompositions should be stable during manufacture and storage and must bepreserved against contamination from microorganisms, such as bacteriaand fungi. The carrier can be a dispersion medium containing, forexample, water, polyol (such as glycerol, propylene glycol, and liquidpolyethylene glycol), and other compatible, suitable mixtures. Variousantibacterial and anti-fungal agents, for example, parabens,chlorobutanol, phenol, ascorbic acid, and thimerosal, can containmicroorganism contamination. Isotonic agents such as sugars,polyalcohols, such as manitol, sorbitol, and sodium chloride can beincluded in the composition. Compositions that can delay absorptioninclude agents such as aluminum monostearate and gelatin.

Sterile injectable solutions can be prepared by incorporating an ironcomplex in the required amount in an appropriate solvent with a singleor combination of ingredients as required, followed by sterilization.Methods of preparation of sterile solids for the preparation of sterileinjectable solutions include vacuum drying and freeze-drying to yield asolid containing the iron complex and any other desired ingredient.

Active compounds may be prepared with carriers that protect the compoundagainst rapid elimination from the body, such as a controlled releaseformulation, including implants and microencapsulated delivery systems.Biodegradable or biocompatible polymers can be used, such as ethylenevinyl acetate, polyanhydrides, polyglycolic acid, collagen,polyorthoesters, and polylactic acid. Such materials can be obtainedcommercially from ALZA Corporation (Mountain View, Calif.) and NOVAPharmaceuticals, Inc. (Lake Elsinore, Calif.), or prepared by one ofskill in the art.

A single unit dose of iron carbohydrate complex may be intravenouslyadministered in a volume of pharmaceutically acceptable carrier of, forexample, about 1000 mg of elemental iron in about 200 ml to about 300 mlof diluent. For example, a single unit dose of iron carbohydrate complexmay be intravenously administered in a volume of pharmaceuticallyacceptable carrier of about 1000 mg of elemental iron in about 250 ml ofdiluent. As another example, a single unit dose of iron carbohydratecomplex may be intravenously administered in a volume ofpharmaceutically acceptable carrier of about 1000 mg of elemental ironin about 215 ml of diluent.

A preferred pharmaceutical composition for use in the methods describedherein contains VIT-45 as the active pharmaceutical ingredient (API)with about 28% weight to weight (m/m) of iron, equivalent to about 53%m/m iron (III)-hydroxide, about 37% m/m of ligand, ≦6% m/m of NaCl, and≦10% m/m of water.

Kits for Pharmaceutical Compositions

Iron complex compositions can be included in a kit, container, pack ordispenser, together with instructions for administration according tothe methods described herein. When the invention is supplied as a kit,the different components of the composition may be packaged in separatecontainers, such as ampules or vials, and admixed immediately beforeuse. Such packaging of the components separately may permit long-termstorage without losing the activity of the components. Kits may alsoinclude reagents in separate containers that facilitate the execution ofa specific test, such as diagnostic tests.

The reagents included in kits can be supplied in containers of any sortsuch that the life of the different components are preserved and are notadsorbed or altered by the materials of the container. For example,sealed glass ampules or vials may contain lyophilized iron complex orbuffer that have been packaged under a neutral non-reacting gas, such asnitrogen. Ampules may consist of any suitable material, such as glass,organic polymers, such as polycarbonate, polystyrene, etc., ceramic,metal or any other material typically employed to hold reagents. Otherexamples of suitable containers include bottles that are fabricated fromsimilar substances as ampules, and envelopes that consist of foil-linedinteriors, such as aluminum or an alloy. Other containers include testtubes, vials, flasks, bottles, syringes, etc. Containers may have asterile access port, such as a bottle having a stopper that can bepierced by a hypodermic injection needle. Other containers may have twocompartments that are separated by a readily removable membrane that,upon removal, permits the components to mix. Removable membranes may beglass, plastic, rubber, etc.

Kits may also be supplied with instructional materials. Instructions maybe printed on paper or other substrate, and/or may be supplied on anelectronic-readable medium, such as a floppy disc, CD-ROM, DVD-ROM,mini-disc, SACD, Zip disc, videotape, audio tape, etc. Detailedinstructions may not be physically associated with the kit; instead, auser may be directed to an internet web site specified by themanufacturer or distributor of the kit, or supplied as electronic mail.

Having described the invention in detail, it will be apparent thatmodifications, variations, and equivalent embodiments are possiblewithout departing the scope of the invention defined in the appendedclaims. It should be understood that all references cited areincorporated herein by reference. Furthermore, it should be appreciatedthat all examples in the present disclosure are provided as non-limitingexamples.

EXAMPLES

The following non-limiting examples are provided to further illustratethe present invention. It should be appreciated by those of skill in theart that the techniques disclosed in the examples that follow representapproaches the inventors have found function well in the practice of theinvention, and thus can be considered to constitute examples of modesfor its practice. However, those of skill in the art should, in light ofthe present disclosure, appreciate that many changes can be made in thespecific embodiments that are disclosed and still obtain a like orsimilar result without departing from the spirit and scope of theinvention.

Example 1 Non-Toxicity Studies

Nonclinical toxicity of VIT-45 is very low, as is normal for Type Ipolynuclear iron (III)-hydroxide carbohydrate complexes. The single dosetoxicity is so low that the LD₅₀ could not be estimated and is higherthan 2000 mg iron/kg b.w. Mice tested with a single dose of 250 mgiron/kg b.w., injected within 2 seconds, showed no signs of illness. Thehighest non-lethal dose level of 1000 mg iron/kg b.w. in mice and ratsis also very high in comparison to a single unit dose of, for example,15 mg iron/kg b.w. once per week in humans. These results providefactors of about 70-fold a human dose, demonstrating a large safetymargin for acute toxicity of the product.

Example 2 Pharmokinetic Studies

Pharmacokinetic and red blood cell measurements of ⁵²Fe/⁵⁹Fe labelledVIT-45 following i.v. administration using PET in 6 patients showed ared blood cell utilization from 61 to 99%. The 3 patients with irondeficiency anemia showed a utilization of radiolabelled iron of 91 to99% after 24 days, compared to 61 to 84% for 3 patients with renalanaemia. The terminal t_(1/2) for VIT-45 was calculated to beapproximately 16 hours, compared to about 6 hours for iron sucrose. Intwo further studies in patients with iron deficiency anemia,pharmacokinetic analyses revealed increases in exposure roughlyproportional with VIT-45 dose (Cmax approximately 150 μg/mL and 320μg/mL following 500 mg and 1000 mg doses, respectively). VIT-45demonstrated a monoexponential elimination pattern with a t_(1/2) in therange 7 to 18 hours. There was negligible renal elimination.

Example 3 Efficacy Studies

The main pharmacodynamic effects of VIT-45 were transient elevations ofserum iron levels, TfS and serum ferritin. These effects were seen inall studies (where measured), following both single doses and repeateddoses. The increase in serum ferritin levels illustrated thereplenishment of the depleted iron stores, which is a well-identifiedand desired effect of iron therapy. In addition, transiently elevatedTfS indicated that iron binding capacity was almost fully utilizedfollowing VIT-45 infusion.

Efficacy of iron replacement therapy is interpreted mainly in terms ofthe ability to normalise Hb levels and iron stores. In the multiple dosestudies, patients demonstrated a slowly-developing, sustained increasein Hb levels during study participation. In one study, 37% and 48% ofpatients in Cohorts 1 and 2, respectively, had achieved normal Hb levelsat the 4-week follow-up visit, and 75% and 73%, respectively, hadachieved a ≧20 g/L increase in Hb on at least 1 occasion.

In another study (patients receiving regular haemodialysis), themajority of patients (61.7%) achieved an increase of Hb of ≧0 g/L at anypoint during the study. Serum ferritin and TfS levels showed a moreprolonged elevation following repeated VIT-45 infusions, indicating asustained replenishment of iron stores. However, elevated levels offerritin and TfS indicating iron overload were avoided. In both of thesestudies, there was a gradual decrease in transferrin over time, alsoindicating successful iron replacement.

Example 4 Safety Assessments

Safety assessments were made in 73 patients with iron deficiency anemia(27 single-dose, 46 repeated-dose), and 166 patients with renal anaemia(3 single-dose, 163 repeated-dose) who received VIT-45 at individualiron doses of 100 mg up to 1000 mg (cumulative doses of 100 to 2200 mg).These studies showed a safety profile equal to, or exceeding, currentlyavailable parenteral iron formulations.

In the single-dose studies, there were few adverse events and no seriousadverse events or withdrawals due to adverse events. There were also norelated clinically relevant adverse changes in vital signs, 12-lead ECGsor laboratory safety tests.

In the repeated-dose studies, there were no deaths attributed to VIT-45,while 10 patients experienced serious adverse events. All of these casesoccurred in patients with renal anaemia receiving haemodialysis and wereconsidered not related to the VIT-45 treatment. Very few patients werewithdrawn from the studies due to treatment-emergent adverse events, andonly 2 withdrawals (due to allergic skin reactions) were consideredpossibly related to treatment. In each of the repeated-dose studies, nopatients experienced clinically significant changes in 12-lead ECGs thatwere related to treatment. There were no consistent changes inlaboratory safety parameters, although there was a low incidence (total6 patients) of laboratory values reported as treatment-relatedtreatment-emergent adverse events (elevated CRP, AST, ALT and GGT,abnormal liver function tests and elevated WBC).

Although many patients in these 2 studies had serum ferritin above 500μg/L on at least 1 occasion during the study, very few patients also hadTfS values>50%. Generally, the elevations of ferritin and TfS were ofshort duration. Iron overload was avoided using the dosing schedulesdefined in the studies.

Example 5 Integrated Safety Studies

The following example demonstrates the safety and effectiveness ofparenteral VIT-45 in the treatment of anemia in a variety of patientpopulations, as determined from several integrated safety studies.

A total of 2429 subjects were treated with VIT-45 or control agents over10 studies that provide safety data for VIT-45. Of these, 1709 subjectsreceived VIT-45 (1095 in completed multicenter studies, 584 inplacebo-controlled, single-dose, crossover studies and 30 inpharmacokinetic studies). The mean total dose of VIT-45 administeredamong the 1095 subjects in the completed multicenter studies wasapproximately 1300 mg; however, some subjects received VIT-45 doses ashigh as 3400 mg. The majority of the subjects treated were able toreceive their calculated iron requirement in only 1 or 2 doses.

Table 2 provides a summary of VIT-45 studies described in this example.

Study A was a single-center, single-dose escalation, randomized,double-blind, placebo-controlled pharmacokinetic study. Subjects weremale and female, between 18 and 45 years of age, inclusive, with mildiron-deficiency anemia. Treatment was a single IV bolus injection ofVIT-45 at 100 mg, 500 mg, 800 mg, or 1000 mg. Examined pharmacokineticparameters included total serum iron and pharmacodynamic (serum ferritinand transferrin, iron binding capacity, % TSATpost, hemoglobin,reticulocyte, and serum transferrin receptor concentrations) endpoints.Examined safety parameters included adverse events, clinical laboratoryevaluations, vital signs, ECG, and physical examinations.

Study B was a single-center, single-dose, open label, uncontrolledpharmacokinetic study. Subjects were between 18 and 75 years of age withiron-deficiency or renal anemia with no other cause of anaemia.Inclusion criteria included hemoglobin concentration between 9 and 13g/dL, no blood transfusions in the previous 3 months, and no history oftreatment with intravenous iron in the last 2 weeks. Treatment was asingle IV bolus injection of VIT-45 at 100 mg labelled with ⁵²Fe and⁵⁹Fe. Examined primary pharmacokinetic parameters included thedistribution of ⁵²Fe and incorporation of ⁵⁹Fe into red blood cells.Examined safety parameters included adverse events, clinical laboratoryevaluations, vital signs, and physical examinations.

Study C was an open-label, multicenter, randomized, multiple-dose,active-controlled postpartum anemia study. Subjects were female,postpartum within 10 days after delivery, with hemoglobin≦10 g/dL atBaseline based on the average of 2 hemoglobin values drawn ≧18 hourspostpartum. Treatment was once weekly doses of VIT-45 for six weeks.VIT-45 dosage was based on the calculated iron deficit (≦2500 mg total).Where screening serum transferrin saturation (TSAT) was ≦20% orscreening ferritin was ≦50 ng/mL, dosage=pre-pregnancy weight(kg)×(15-baseline hemoglobin [g/dL])×2.4+500 mg. Where screening TSATwas >20% and screening ferritin was >50 ng/mL, dosage=pre-pregnancyweight (kg)×(15-baseline hemoglobin [g/dL])×2.4. Infusion of VIT-45 wasas follows: ≦200 mg, administered as an undiluted intravenous push (IVP)over 1-2 minutes; 300-400 mg, administered in 100 cc normal salinesolution (NSS) over 6 minutes; 500-1,000 mg administered in 250 cc NSSover 15 minutes. For primary efficacy, “success” was defined as anincrease in hemoglobin of ≧2 g/dL anytime between baseline and end ofstudy or time of intervention, while “failure” was defined as <2 g/dLincrease in hemoglobin at all times between baseline and end of study ortime of intervention. Examined safety parameters included adverseevents, clinical laboratory evaluations, vital signs, and physicalexaminations.

Study D was a multicenter, open-label, randomized, active-controlled,multiple-dose postpartum anemia study. Subjects were adult women ≧18years old with postpartum anaemia within 6 days after delivery.Treatment was administered once-weekly for a maximum of 3 infusions.Patients received IV infusions of 16.7 mL/min to deliver a maximum doseof 1000 mg iron per infusion. Patients received VIT-45 infusions onceweekly for up to 3 occasions until the calculated cumulative dose wasreached. Patients ≦66 kg received a minimum dose of 200 mg and a maximumdose of 15 mg iron/kg during each infusion. Patients >66 kg received adose of 1000 mg on the first dosing occasion, and a minimum dose of 200mg and a maximum dose of 1000 mg at each subsequent dosing. Doses of200-400 mg were diluted in 100 cc NSS and 500-1000 mg were diluted in250 cc NSS. Primary efficacy was examined as change from baseline levelsof hemoglobin to Week 12. Examined safety parameters included adverseevents in the mother and breast-fed infant, adverse events leading todiscontinuation of treatment, vital signs, 12-lead electrocardiogram(ECG), physical examinations, and clinical laboratory panels.

Study E was a multicenter, open-label, randomized, active-controlled,multiple-dose hemodialysis-associated anemia study. Subjects were adultmale or female subjects between the ages of 18 and 80 years (inclusive)requiring haemodialysis with iron deficiency secondary to chronic renalfailure. Dosing started on Day 1, Week 0 for both treatment arms andcontinued 2 or 3 times weekly until the individual calculated cumulativedose was reached. Patients received 200 mg VIT-45 during their scheduledhaemodialysis sessions (2-3 sessions/week) until the calculatedcumulative dose was reached. Cumulative total iron requirement wascalculated for each patient using the Ganzoni formula. Primary Efficacywas examined as the percentage of patients reaching an increase inhemoglobin≧10 g/L at 4 weeks after baseline. Examined safety parametersincluded adverse events, vital signs, 12-lead ECG, physicalexaminations, and clinical laboratory evaluations.

Study F was a multicenter, open-label, multiple dose, uncontrolledhemodialysis-associated anemia study. Subjects were male and femalepatients 18-65 years of age, inclusive, with haemodialysis-associatedanaemia undergoing maintenance haemodialysis. Treatment duration was amaximum of six weeks. Patients received 200 mg VIT-45 during theirscheduled haemodialysis sessions (2-3 sessions/week) until thecalculated cumulative dose was reached. Cumulative total ironrequirement was calculated for each patient using the Ganzoni formula.Efficicacy was examined as correction of iron deficiency and hemoglobinconcentration of the patient. Examined safety parameters includedadverse events, vital signs, 12-lead ECG, physical examinations,haematology and blood chemistry profiles, and urea reduction ratio.

Study G was a multicenter, multiple-dose open-label, uncontrolledgastrointestinal disorder-associated anemia study. Subjects were malesand females between 18 and 60 years of age, inclusive, with moderatestable iron-deficiency anemia secondary to a gastrointestinal disorderand a calculated total iron requirement ≧1000 mg; ≧50% of patients ineach cohort were to require ≧1500 mg total iron. Duration of treatmentwas single doses at weekly intervals for up to 4 weeks (Cohort 1) or 2weeks (Cohort 2). Administration of VIT-45 was by IV bolus injection of500 mg (Cohort 1) or 1000 mg (Cohort 2), where total iron requirementfor each patient, which determined how many weekly infusions werereceived, was calculated using the formula of Ganzoni. Examinedpharmacokinetic parameters included total serum iron and pharmacodynamic(hemoglobin, ferritin, TSAT) endpoints. Examined safety parametersincluded adverse events, clinical laboratory evaluations, vital signs,ECG, physical examinations, and elevated serum ferritin (>500 μg/L) ANDelevated TSAT (>45%).

Study H was a multicenter, multiple-dose randomized, open-label,active-controlled gastrointestinal disorder-associated anemia study.Subjects were males and females aged 18 to 80 years, inclusive, withiron-deficiency anaemia secondary to chronic inflammatory bowel disease(ulcerative colitis or Crohn's disease) and a calculated total ironrequirement of at least 1000 mg total iron. Treatment was weekly VIT-45infusions, with a maximum of 3 infusions permitted in a single treatmentcycle. Administration consisted of an infusion on Day 1, with subsequentinfusions at weekly intervals up to a maximum of 1000 mg iron per dose.The doses were continued until the patient received the cumulative dosebased on their individual requirement for iron. Primary efficacy wasexamined as change from baseline to Week 12 in hemoglobin. Examinedsafety parameters included adverse events, vital signs, 12-lead ECG,physical examinations, and clinical laboratory evaluations.

Study I was an open label, multiple-dose, multicenter, randomized,active-control anemia due to heavy uterine bleeding study. Subjects werefemales at least 18 years of age with iron-deficiency anemia secondaryto heavy uterine bleeding. Duration of treatment was six weeks. VIT-45dosage was based on the calculated iron deficit as follows: wherebaseline TSAT≦20% or baseline ferritin≦50 ng/mL, VIT-45 total dose inmg=baseline weight (kg)×(15-baseline hemoglobin [g/dL])×2.4+500; wherebaseline TSAT>20% and baseline ferritin>50 ng/mL, VIT-45 total dose inmg=baseline weight (kg)×(15-baseline hemoglobin [g/dL])×2.4. Foradministration, ≦200 mg was administered as an undiluted IVP over 1-2minutes; 300-400 mg was administered in 100 cc NSS over 6 minutes; and500-1,000 mg was administered in 250 cc NSS over 15 minutes. Primaryefficacy was examined as the proportion of subjects achieving success,defined as an increase in hemoglobin of ≧2.0 g/dL anytime betweenbaseline and end of study or time of intervention. Examined safetyparameters included adverse events, clinical laboratory evaluations,vital signs, and physical examinations.

Study J was a multicenter, single-dose blinded, randomized,placebo-controlled crossover iron deficiency anemia study. Subjects weremale or female, at least 18 years of age, with a hemoglobin≦12 g/dL,TSAT≦25%, and ferritin<300 ng/mL (iron-deficiency anemia due to dialysisor non-dialysis dependent chronic kidney disease or inflammatory boweldisease), or ferritin≦100 ng/mL (iron-deficiency anemia due to otherconditions). Treatment was two single doses seven days apart.Administration of VIT-45 occurred over 15 minutes and was ≦1000 mg (15mg/kg for weight≦66 kg). For pharmacokinetic variables, total serum ironwas assessed using Atomic Absorption methodology. Examined safetyparameters included adverse events, clinical laboratory evaluations,vital signs, and physical examinations.

TABLE 2 Summary of Safety Studies of VIT-45 Study Number SubjectsIntravenous Dose(s) of VIT-45 Comparator Pharmacokinetic Studies ATotal: 32 Single doses of: Placebo VIT-45: 24 100 mg via bolus injection500 mg, 800 mg, 1000 mg diluted in 250 mL of NSS administered by IVinfusion over 15 minutes B Total: 6 Single dose of 100 mg labelled with⁵²Fe and ⁵⁹Fe None VIT-45: 6 administered as an IV injection over 10minutes Studies in Subjects with Postpartum Anemia C Total: 352Cumulative total iron requirement was calculated Oral iron VIT-45: 174for each patient. Patients received IV infusions (ferrous sulfate) todeliver a maximum dose of 1000 mg iron per 325 mg TID infusion. Patientsreceived VIT-45 infusions for 6 weeks once weekly until the calculatedcumulative dose was reached or a maximum of 2500 mg had beenadministered. Doses ≦200 mg were administered IV push over 1-2 minutes;doses of 300-400 mg were diluted in 100 cc NSS and administered over 6minutes; doses of 500-1000 mg were diluted in 250 cc NSS andadministered over 15 minutes. D Total: 344 Cumulative total ironrequirement was calculated Oral iron VIT-45: 227 for each patient usingthe Ganzoni formula. (ferrous sulfate) 100 mg BID for 12 weeks Studiesin Subjects Undergoing Hemodialysis E Total: 237 Patients received 200mg IV bolus injection of Venofer ®; patients VIT-45: 119 study drugduring their scheduled hemodialysis received 200 mg IV sessions (2-3sessions/week) until the injection over 10 calculated cumulative dosewas reached. minutes of study Cumulative total iron requirement wascalculated drug during their for each patient using the Ganzoni formula.scheduled hemodialysis sessions (2-3 sessions/week) until the calculatedcumulative dose was reached. Cumulative total iron requirement wascalculated for each patient using the Ganzoni formula.^(a) F Total: 163Patients received 200 mg IV push of study drug None VIT-45: 162 duringtheir scheduled hemodialysis sessions (2-3 sessions/week) until thecalculated cumulative dose was reached. Cumulative total ironrequirement was calculated for each patient using the Ganzoni formula.Studies in Subjects with Gastrointestinal Disorders G Total: 46 500 mgor 1000 mg iron by IV infusion at weekly None VIT-45: 46 intervals forup to 4 weeks (500 mg) or 2 weeks (1000 mg); maximum total dose of 2000mg. The last dose could have been less, depending on the calculatedtotal iron requirement. Doses were diluted in 250 cc NSS andadministered by IV infusion over 15 minutes. H Total: 200 Cumulativetotal iron requirement was calculated Oral iron VIT-45: 137 for eachpatient using the Ganzoni formula. (ferrous sulfate) 100 mg BID for 12weeks Study in Subjects with Heavy Uterine Bleeding I Total: 456 ≦1000mg/week (15 mg/kg for weight ≦66 kg); Oral iron VIT-45: 230 patientsreceived VIT-45 infusions once weekly (ferrous sulfate) until thecalculated cumulative dose was reached 325 mg TID or a maximum of 2500mg had been administered. for 6 weeks Doses ≦200 mg were administered IVpush over 1-2 minutes; doses of 300-400 mg were diluted in 100 cc NSSand administered over 6 minutes; doses of 500-1000 mg were diluted in250 cc NSS and administered over 15 minutes. Study in Subjects with IronDeficiency Anemia J Total: 594 Single dose of ≦1000 mg by IV infusionover 15 Placebo VIT-45: 584 minutes (15 mg/kg for weight ≦66 kg). Doses≦500 mg were diluted in 100 cc NSS and doses of >500- 1000 mg werediluted in 250 cc NSS. Pharmacokinetic subjects: single 1,000 mg dose byIV infusion

The majority of the subjects who received VIT-45 completed the study.The incidence of premature discontinuations in the completed multicenterstudies was 10% in the VIT-45 group which is comparable to that observedin the oral iron (9.6%) and Venofer (13.6%) groups. Reasons forpremature discontinuation were generally comparable among the treatmentgroups, except that the incidence of adverse events leading todiscontinuation were higher in the Venofer group (5.9%) compared to theVIT-45 (1.8%) and oral iron (2.1%) groups, demonstrating the overalltolerability of VIT-45.

The overall incidences of treatment-emergent adverse events werecomparable between the VIT-45 (49.5%) and oral iron (51.2%) groups inthe completed multicenter studies; the incidence in the Venofer groupwas lower (39.0%); however, the number of subjects in the VIT-45 groupis almost 10-fold that of the Venofer group. Treatment-emergent adverseevents experienced by ≧2% of the 1095 VIT-45 subjects included headache(8.6%), abdominal pain (2.5%), nausea (2.4%), blood phosphate decreased(2.4%), hypertension (2.2%), nasopharyngitis (2.0%), and hypotension(2.0%). As expected, the most notable difference between subjectstreated with VIT-45 and those treated with oral iron was for theincidence of gastrointestinal events (31.0% vs. 12.8%), specifically theincidences of constipation, diarrhea, nausea, and vomiting, which weremore than double that observed in the VIT-45 group.

In the calculated dose/first-dose 1,000 mg studies, no statisticallysignificant difference was observed between the VIT-45 (49.5%) and oraliron (51.2%) groups for the overall incidence of treatment-emergentadverse events. The incidence of gastrointestinal disorders wasstatistically significantly (p<0.0001) higher in the oral iron group(31.0%) compared to the VIT-45 group (15.2%), while the incidences ofadverse events associated with investigations and skin and subcutaneoustissue disorders were statistically significantly higher in the VIT-45group (9.1% and 7.3%, respectively) compared to the oral iron group(3.9% and 2.4%, respectively). Among the gastrointestinal disorders,greater proportions of subjects in the oral iron group than the VIT-45group experienced constipation, nausea, diarrhea, and vomiting, while agreater proportion of VIT-45 subjects experienced abdominal pain thanoral iron subjects. Among the adverse events associated withinvestigations, greater proportions of VIT-45 subjects experienced bloodphosphate decreased and GGT increased than oral iron subjects. Among theadverse events associated with skin and subcutaneous tissue disorders,greater proportions of VIT-45 subjects experienced rash and pruritusthan oral iron subjects.

The only drug-related treatment-emergent adverse events reported by atleast 2% of VIT-45 subjects in the calculated dose/first-dose 1,000 mgstudies were headache (3.9%) and blood phosphate decreased (3.3%). Theincidence of treatment-emergent adverse events reported on the first dayof dosing in the calculated dose/first-dose 1,000 mg studies wasstatistically significant higher in the VIT-45 group compared to theoral iron group (6.8% vs. 2.7%). On the first day of dosing, the VIT-45group had statistically significantly greater proportions of subjectswho experienced general disorders and administration site conditions,primarily events associated with the site of study drug infusion, andskin and subcutaneous tissue disorders, primarily rash and urticaria,compared to the oral iron group.

The overall incidence of treatment-emergent adverse events was similaramong VIT-45 subjects treated with either the 200 mg or 1000 mg doses.The only notable difference was for the higher incidence of headache inthe 1000-mg group, which was almost double that observed for the 200-mggroup. No meaningful trends were apparent with respect to the incidenceof treatment-emergent adverse events when analyzed by gender, age, race,weight, or etiology of anemia.

There were no deaths in the study attributed to VIT-45. The incidence ofother serious adverse events among VIT-45 subjects was low (3% in allcompleted multicenter studies and 0.3% in the placebo-controlled,single-dose crossover study) and none were considered related to studydrug. The incidence of premature discontinuation due to adverse eventswas comparable between the VIT-45 group (2.1%) and the other activetreatment groups (3.1% oral iron and 2.5% Venofer). The incidence ofdrug-related treatment-emergent adverse events of hypersensitivity was0.2%, the same as that observed with oral iron (0.2%). Drug-related mildor moderate hypotension was observed in 4 (0.2%) VIT-45 subjects, noneof which were considered serious, led to premature discontinuation, orwere symptomatic. Treatment-emergent adverse events indicative ofpotential allergic reactions including rash, pruritus, and urticariawere reported by <2% of subjects who were treated with VIT-45; none ofthese events was considered serious and few led to prematurediscontinuation.

Laboratory evaluations of mean changes from baseline and potentiallyclinically significant values demonstrated no clinically meaningfulchanges for the majority of the parameters evaluated. However, duringthe conduct of the latter portion of the clinical program, transient,asymptomatic decreases in blood phosphate levels were observed amongsubjects treated with VIT-45. The decreases were apparent approximately7 days after the initial dose of VIT-45 and the median time to recoverywas approximately 2 weeks. No subjects reported an adverse event thatwas related to serum phosphate and no subject discontinued from thestudy due to decreased serum phosphate. The only predictor of change inserum phosphate was that subjects with higher baseline serum phosphatevalues had larger decreases in serum phosphate. The fact that themajority of oral iron-treated subjects also had a post-baseline decreasein phosphate and the negative correlation of baseline serum phosphatewith changes in serum phosphate for both the VIT-45 and oral irontreatment groups suggest that the mechanism is intrinsic to iron therapyin this severely anemic population.

Overall, no clinically meaningful changes in vitals signs evaluationswere associated with VIT-45 administration.

Safety data from more than 1700 subjects demonstrate the safety andtolerability of VIT-45.

What is claimed is:
 1. A method of treating a disease, disorder, orcondition characterized by iron deficiency or dysfunctional ironmetabolism resulting in reduced bioavailability of dietary iron,comprising administering to a subject in need thereof an ironcarbohydrate complex in a single dosage unit of at least about 0.6 gramsof elemental iron, wherein, the iron carbohydrate complex is selectedfrom the group consisting of an iron mannitol complex, and an ironpolyisomaltose complex, an iron polymaltose complex, an iron gluconatecomplex, and an iron sorbitol complex, the iron carbohydrate complex hasa substantially non-immunogenic carbohydrate component, and the disease,disorder or condition is not Restless Leg Syndrome.
 2. The method ofclaim 1, wherein the iron carbohydrate complex has substantially nocross reactivity with anti-dextran antibodies.
 3. The method of claim 1,wherein the disease, disorder, or condition comprises anemia.
 4. Themethod of claim 3, wherein the anemia comprises iron deficiency anemia.5. The method of claim 3, wherein: (i) the anemia comprises an irondeficiency anemia associated with chronic blood loss; acute blood loss;pregnancy; childbirth; childhood development; psychomotor and cognitivedevelopment in children; breath holding spells; heavy uterine bleeding;menstruation; chronic recurrent hemoptysis; idiopathic pulmonarysiderosis; chronic internal bleeding; gastrointestinal bleeding;parasitic infections; chronic kidney disease; dialysis; surgery or acutetrauma; and chronic ingestion of alcohol, chronic ingestion ofsalicylates, chronic ingestion of steroids; chronic ingestion ofnon-steroidal anti-inflammatory agents, or chronic ingestion oferythropoiesis stimulating agents; (ii) the anemia is of a chronicdisease selected from the group consisting of rheumatoid arthritis;cancer; Hodgkins leukemia; non-Hodgkins leukemia; cancer chemotherapy;inflammatory bowel disease; ulcerative colitis thyroiditis; hepatitis;systemic lupus erythematosus; polymyalgia rheumatica; scleroderma; mixedconnective tissue disease; Sojgren's syndrome; congestive heartfailure/cardiomyopathy; and idiopathic geriatric anemia; (iii) theanemia is due to impaired iron absorption or poor nutrition; (iv) theanemia is associated with Crohn's Disease; gastric surgery; ingestion ofdrug products that inhibit iron absorption; or chronic use of calcium.6. The method of claim 1 wherein the disease, disorder, or condition isselected from the group consisting of blood donation; hair loss; andattention deficit disorder.
 7. The method of claim 1 wherein the singledosage unit of elemental iron is at least about 1.0 grams.
 8. The methodof claim 1 wherein the single dosage unit of elemental iron is at leastabout 1.5 grams.
 9. The method of claim 1 wherein the single dosage unitof elemental iron is at least about 2.0 grams.
 10. The method of claim 1wherein the single dosage unit of elemental iron is administered inabout 15 minutes or less.
 11. The method of claim 1 wherein the singledosage unit of elemental iron is administered in about 5 minutes orless.
 12. The method of claim 1, wherein the iron carbohydrate complexis an iron polyglucose sorbitol carboxymethyl ether complex.
 13. Themethod of claim 12, wherein the iron polyglucose sorbitol carboxymethylether complex is a polyglucose sorbitol carboxymethyl ether-coatednon-stoichiometric magnetite complex.
 14. The method of claim 1, whereinmean iron core size is at least about 1 nm but no greater than about 9nm; or mean size of a particle of the iron carbohydrate complex is nogreater than about 35 nm.
 15. The method of claim 1, wherein the ironcarbohydrate complex is administered parenterally.
 16. The method ofclaim 15, wherein (i) parenteral administration comprises intravenousinfusion and the single unit dose of iron carbohydrate complex isadministered at a concentration of about 1000 mg elemental iron in about200 ml to about 300 ml of diluent; (ii) parenteral administrationcomprises bolus injection and the single unit dose of iron carbohydratecomplex is administered at a concentration of about 1000 mg elementaliron in about 200 ml to about 300 ml of diluent; or (iii) parenteraladministration comprises intramuscular injection and the single unitdose of iron carbohydrate complex is administered at a concentration ofabout 500mg elemental iron in less than about 10 ml diluent.
 17. Themethod of claim 1 further comprising a second administration of saidiron carbohydrate complex upon recurrence of at least one symptom of thedisease, disorder, or condition.
 18. The method of claim 1 wherein thesingle dosage unit of elemental iron is administered in about 2 minutesor less.
 19. The method of claim 1 wherein the single dosage unit ofelemental iron is greater than 1.0 grams.
 20. The method of claim 1wherein the iron carbohydrate complex is an iron mannitol complex. 21.The method of claim 1 wherein the iron carbohydrate complex is an ironpolyisomaltose complex.
 22. The method of claim 1 wherein the ironcarbohydrate complex is an iron gluconate complex.
 23. The method ofclaim 1 wherein the iron carbohydrate complex is an iron sorbitolcomplex.